Developing device for use in electrophotographic copying machines

ABSTRACT

An image developing device for an electrophotographic copying machine requiring a replenished supply of a developing agent wherein a lever is pivotally mounted for operation by a rotating cam to advance a ratchet wheel for intermittently withdrawing the developing agent from a reservoir.

United States Patent [1 1 [111 3,912,388

Takahashi et al. Oct. 14, 1975 [54] DEVELOPING DEVICE FOR USE IN [52] US. Cl. 355/3 DD; 118/637; 427/18 ELECTROPHOTOGRAPHIC COPYING [51] Int. Cl. G03G 15/08; G036 15/09 MACHINES [58] Field of Search 355/3 DD, 3 R; 118/637; 96 1 SD; 222 DIG. l; 427 18 [75] Inventors: Isao Takahashi, Yokohama;

Motoharu Fujii, Tokyo; Kazuo Kawakubo, Hino; M asao Ariga, [5 6] References Clled Komae; Susumu Sugiura, Yamato, STATES PATENTS all Of Japan 2,965,266 I 12/1960 Rutkus et a1 96/1 SD 73 A =c Kab h'kiKa'h Tk, 1 sslgnee il? us 1 Is 0 yo Primary ExaminerRobert P. Gremer Attorney, Agent, or Firm-Fitzpatrick, Cella, Harper 22] Filed: Aug. 23, 1974 & s i t [21] Appl. No.: 499,985

[57] ABSTRACT Related US Application Data An image developing device for an electrophoto [62] g z g ggs i g y fig sgg gi g graphic copying machine requiring a replenished sup- NO 3 764 208 ply of a developing agent wherein a lever is pivotally mounted for operation by a rotating cam to advance a [30] Forei n Ap cation Priority D ata ratchet wheel for intermittently withdrawing the de- D 29 I g /O 45127212 veloping agent from a reservoir.

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FIG. 5

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FIG.|3

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1. In an image developing device including a housing, a reservoir for a developing agent mounted on the housing, and a shaft which rotates during operation of said device, wherein said device requires a replenished supply of said developing agent during said operation, the improvement comprising developing means for applying said developing agent to an object to be developed, a cam plate fixed obliquely on said rotatable shaft, a lever pivotally mounted intermediate its length and having a ratchet pawl on one end, means for urging the other end of said lever against said cam plate, a ratchet wheel mounted for rotation by said pawl, and developer agent supply means operable upon rotation of said ratchet wheel to withdraw said developer agent from said reservoir and supply it to said developing means, said developer agent supply means including a supply roller having an irregular outer-surface, said reservoir having an opening in a bottom portion thereof in which opening said supply roller is mounted.
 2. A developing device according to claim 1, wherein said lever is pivotally mounted on a shaft fixedly provided on the housing, and said urging means comprises a spring member extended between said lever and said housing for bringing said other end of said lever into pressure contact with said oblique caM plate.
 3. A developing device according to claim 1, wherein said developing means comprises a magnetic brush roller and said supply means includes a screw roller for transporting said developing agent.
 4. A developing device according to claim 3, wherein said oblique plate cam is fixedly provided on said screw roller. 